If you’re a fan of both Supernaturaland web superstar/Whedonverse alum Felicia Day, then tonight’s episode of the CW series (airing at 9/8c) will likely leave you in a state of complete nerdvana. It certainly did for the actress, who calls the guest spot an “awesome dream come true.”

“In the middle of prepping all these web series I’m doing, [the Supernatural producers] called up and said, ‘Hey, we have the perfect part for you. Would you like to be in an episode?’” she recalls. “I didn’t really have the time, but I could never say anything but, ‘Yes.’

“Supernatural is one of those [shows] that I’ve actually wanted to be on for years, and I always questioned why I wasn’t getting on the show,” she adds with a laugh. “I really like the tone of the show and the vibe.”

So what was it like making the dream a reality and working with stars Jared Padalecki and Jensen Ackles? “I’m someone who works behind a computer,” she replies. “These are like jock guys. The set is so informal and really accepting. But [there’s] a lot of testosterone, and it hit me in the face… But in a good way!”

Day guest stars as Charlie, a brilliant, unsuspecting hacker who works in IT at the Leviathan boss’ Richard Roman Enterprises. It’s a part that the actress definitely related to thanks to some unusual childhood ambitions. “When I was a kid, I actually wanted to be a hacker,” she shares. “I made my mom buy that magazine 2600, but didn’t really follow-through to actually become a crack hacker.”

Add to that Charlie’s genre-tastic decorations, and Day was right at home. “[Charlie] loves Lord of the Rings and Harry Potter and comic books,” she describes. “When I walked on the set of my apartment, all the set dressing seemed to be things I owned or friends of mine owned or things that I’ve seen at Comic-Con.”

While the computer expert might be in over her head when she first finds herself caught in Dean and Sam’s battle with Dick Roman, she’ll be “swimming upward” as she works with the Winchesters. “By the end of the episode, there’s a really interesting equilibrium [with] the guys,” she says. “Being forced to work together, in a sense, [made] Charlie their equal. At least, in her head, she was.

“Charlie isn’t necessarily like other characters I’ve played in the past. She actually is a lot stronger and a lot less nervous in a way,” she adds. That’s not to say there isn’t a funny quality to the character that viewers have come to expect from the comedically-gifted actress. Even amid a high-stakes Leviathan war, there are some particularly hilarious “lines in the episode that fans will definitely be quoting online after or during the broadcast.”

Now that Day can cross Supernatural off her bucket list, what other genre shows would she like to grace? “I would love to be on Game of Thrones, but I’m not British,” she replies. “And I would love to be on True Blood, but I don’t want to show any nudity. It would be too awkward for me to do nudity because animated gifs would pop up immediately. I’m online too much. I couldn’t do it.”